1. Field of the Invention
This invention has relation to apparatus useful for clearing out conduits and for thawing out frozen water lines whether or not those lines and conducts can withstand high pressure, mechanical deformation, or the application of excessive heat.
2. Description of the Prior Art
For many years, iron water pipes have been cleared of ice by attaching heavy electrodes on either side of the frozen portions and passing heavy current between the electrodes thus heating the pipe to melt the ice. Such methods are of no value when there can be no access to both ends of a frozen portion of metallic pipe. Obviously, this method is of no value with plastic pipe or other pipe which is a nonconductor of electricity.
Blow torches have been used very effectively in the past to melt ice in metal pipes. This option is not available for use with pipes which cannot withstand the heat.
It is known to clear conduits of ice by inserting flexible tubing or hosing into the frozen conduits and forcing steam through the tubing to melt the ice in the conduit. See ancient U.S. Pat. No. 77,857 granted to Young on May 12, 1868. In the disclosure of that patent, the steam discharges upwardly from a horizontal pipe situated in horizontal alignment with the conduit to be cleared. It appears that the melted ice water and any condensed steam would run right back out of the feed pipe onto the ground.
Structures showing hot water forced from a tube into a horizontal pipe to melt the ice, with the melted ice water and the water for melting which was forced into the frozen conduit running back onto the ground, are shown in U.S. Pat. No. 458,503 granted to Simpson on Aug. 25, 1891; U.S. Pat. No. 29,204 also to Simpson, granted on Nov. 13, 1894; and U.S. Pat. No. 1,361,023 granted to Darley on Dec. 7, 1920.
Closed circuit systems for forcing hot water into frozen pipes and then returning that water to heat boilers to once again be circulated into the pipe are shown in U.S. Pat. No. 1,243,973 granted to Philippon on Oct. 23, 1917 and U.S Pat. No. 4,449,553 granted to Sullivan et al on May 22, 1984. These systems are not designed in such a way that a water thawing apparatus can easily be transported to any location where needed, and where the actual melting operation is carried out using components which are at all times open to the atmosphere. The Philippon and Sullivan patents are designed to obtain results similar to that achieved with the present invention; but in a much more awkward, expensive and unwieldy manner.
Another apparatus for clearing frozen water lines which is subject to some of the same objections as the apparatus shown in the Philippon and Sullivan patents is shown in U.S. Pat. No. 4,250,925 granted to Mast on Feb. 17, 1981. The Mast structure contemplates running a flexible tube into a frozen conduit, and having the recirculating heated water and thawed ice water drop into a relatively huge holding tank from whence the water is sucked into a heater and then pumped through a coil of tubing back into the frozen conduit. The structure suffers from the disadvantage that when the ice block is cleared, the water pressure in the far end of the unblocked conduit will rush into the return line or hose means and will freely spray out of the "end 38, opening to the atmosphere". See the specification of the patent to Mast, column 3, paragraph beginning on line 54.
What was missing before the present invention was a portable device capable of being moved into an area adjacent to an open end of a conduit blocked by ice, which apparatus can remove the ice blockage whether or not water pressure is present at the other end of the conduit on the other side of the block, and to accomplish this result without any loss of water from the system in the room, on the floor, or in whatever other environment the open end of the frozen conduit is present.
None of the prior art cited above or known to the applicant and those in privity with him can be used without the exercise of inventive faculty to clear from one end thereof obstructions such as scale and other deposits.
Neither applicant nor those in privity with him are aware of any prior art which is closer than that discussed above or which anticipates the claims set out herein.